Harpoons being WEIRD

I launched 8 harpoons at a Udaloy leading a formation and when they reached something like 1 nm away, they popped up to 3500 ft before diving. This has been happening all through the scenarios I’ve done of late. If they get through they hit like a tomahawk does. Also, on the occasion I spoke of at the beginning, that udaloy shot down 18 harpoons, while being jammed by 2 ea-6s at the same time